1. Field of the Invention
This invention relates to chain saw sharpeners and, more particularly to chain saw sharpeners having a fixed clamp and a guide member.
2. Description of the Prior Art
In sharpening the teeth of a chain saw, it is important that the file be firmly supported at a selected angle to the tooth to be sharpened, while at the same time, permitting convenient reciprocating motion as the file engages the teeth and rotational motion to bring the file into contact with and removal from the teeth. A number of inventions have been devise to accomplish these functions as typified by U.S. Pat. No. 2,421,657, issued to J. H. Speed for hand saws and U.S. Pat. Nos. 2,900,850, issued to R. L. Travis; 2,995,959, issued to C. C. Mills; 3,027,784, issued to W. G. Weatherly; and 4,177,697, issued to E. McDunn for chains saws.
It is very desirable, also, to have a file which may readily be removed from its file guide for reasons of portability; exchange of files, when desired; and for storage, as shown by Weatherly. But, it is equally important that the file not be cantilevered, but rather firmly supported by spaced support members, adjacent the ends of the file, as shown by the other references. No chain saw sharpeners are known which provide both functions.
Additionally, for purposes of clearing metallic filings from the grooves and ridges of the file; for even wearing of the file; for ability to twist the file during the sharpening process for obtaining a superior cutting edge and for placement of the file relative to the link supported tooth, it is desirable that the circular file itself be rotatable within its mountings. Such structure is unknown in chain saw sharpeners.